YouTube defaults to autoplay for adult users because continuous playback serves Alphabet’s business model: each additional video creates another chance to show ads. The company’s recommendation engine selects follow-up videos based on viewing history, making it likely viewers will keep watching, which in turn increases ad impressions. That convenience is also a revenue lever, and it is why the toggle is switched on from the start.
Users who prefer to stop after one video can turn the feature off almost anywhere. On phones and tablets, the toggle sits at the top of the player, or under Settings > Playback. On desktop, the control is at the bottom of the video player. On TVs and consoles, it appears under Settings in the account menu. Those who cast from a phone can toggle it from the queue as well.
There are a few caveats. Autoplay is disabled by default for users aged 13 to 17, and on supervised accounts parents can lock it off entirely. Also, autoplay does not run indefinitely: playback stops after 30 minutes on a mobile network and after four hours on Wi-Fi, giving viewers a natural break even if they forget to change the setting.